The following table provides the criteria to select the appropriate level of information associated with a geothermal project's research and development. Select the category/term that best corresponds to the current stage of the project.

Level of Information: Qualifying Criteria and Barriers

Proposed Terms

Description

Stage of Modeling

Qualifying Criteria

Identified

Proven

The reservoir’s production has been evaluated with more than one successful commercial well, and is supported by extensive evidence from geophysical, geochemical, and geologic surveys.

Very Advanced Conceptual, Advanced Reservoir – Includes multiple estimates of reservoir volume and temperature, includes local variations and multi-well drawdown effects

For a resource to be considered ”Proven", all of the following criteria must be met:

Multiple, full-scale production and injection wells have been drilled and are capable of being placed online.

Well field built out and capable of producing expected flow

Confirmed

The reservoir’s production has been evaluated with more than one successful commercial well, and is supported by extensive evidence from geophysical, geochemical, and geologic surveys.

Very Advanced Conceptual, Intermediate Reservoir – Includes multiple estimates of reservoir volume and temperature, includes local variations and multi-well drawdown effects

For a resource to be considered "Confirmed," all of the following criteria must be met:

Two or more full-scale wells must be drilled and flow tested

Multiple full-diameter wells drilled

Demonstrated

Both of these requirements must be met:

The reservoir has been evaluated with successful flow tests (from slim holes and/or 1 successful production well), and

For a resource to be considered Potential, all of the following criteria must be met:

Temperature is measured at the reservoir level using at least one of the following methods:

Downhole probe in slimhole(s) drilled into the reservoir

Temperature is corroborated using at least one of the following methods:

Downhole geothermometry

Assessment of lithology and mineral assemblages taken from cores and/or cuttings

Conceptual model is refined using downhole geophysics

Drill slim/core hole

Inferred

Estimates of temperature and volume for the reservoir are based on minimal estimates and/or surficial geophysical, structural, and geochemical evidence.

Rudimentary Conceptual- few converging estimates of reservoir temperature and volume, but use of the volume method.

For a resource to be considered Inferred, both of the following criteria must be met:

Temperature is estimated using at least one of the following methods:

a well-executed geothermometry

thermal gradient holes

Conceptual model of the reservoir is supported by data from surface geophysical surveys

Field testing/sampling

Undiscovered

Estimates of temperature and volume of the geothermal resource are largely theoretical, i.e. without specific research studies - interpolated from the visible existence of surface manifestations and/or fracturing, and/or from analogous structural and hydrological settings.

Not enough information exists on the resource to construct a reservoir model – theoretical calculation of heat-in-place alone.

For a resource to be considered Undiscovered, the potential is estimated by at least one of the following activities:

field mapping - structural, surface manifestations, etc.

shallow heat flow studies

extrapoloation of third-party data

remote sensing

For those familiar with other reporting standards, the following table attempts to show an approximate correspondence of the GRRM terminology to other terms. This matching is not to be taken as an exact cross-walk between terminologies, but simply as a reference point to better select the appropriate GRRM term.